Southern California -- this just in

Occupy L.A.: Tense standoff underway as LAPD, protesters face off

As the Los Angeles Police Department was poised to evict the Occupy L.A. camp at City Hall, a crowd was growing at the corner of First Street and Broadway seeking to join the demonstrators.

A line of about 12 police officers in riot gear was blocking the street as about 100 demonstrators chanted and shot photos. Clusters of protesters shouted: "You're hella old! Are you going to be on the side of Dr. King?"

The tense scene came as the LAPD closed off an area from Temple Street on the north to 3rd Street on the south and Alameda Street on the east and Broadway on the west.

An LAPD helicopter announced the commencement of the department's action, swooping down low and incessantly circling the City Hall steps on which hundreds of protesters had gathered.

It flooded the camp with rays from its high-powered searchlight and the din from its propellers threatened to drown out a chant of "Occupy L.A., all day, all night!" by the protesters.

Someone then launched fireworks over the camp.

Officials also issued a citywide tactical alert. Los Angeles police have not said when they will evict the protesters. An LAPD email alert said the tactical alert was "due to unusual occurrence in downtown L.A." The LAPD was beginning to put up traffic barriers along streets around City Hall.

Several people reported seeing large numbers of police cars driving into Dodger Stadium, where officers were apparently gathering.

Some activists placed trash cans and recycling bins to block the main entrance to the lawn, saying they saw the barrier as some level of protection against the expected eviction.

The LAPD had set a Monday morning deadline for the protesters to leave.

At a meeting of demonstrators Tuesday evening, organizers said that it was "very probable" that some kind of raid will occur Tuesday. They did not reveal the source of the information.

An excited man ran through the camp screaming: "The cops are coming from the northeast side! The cops are coming!" His Paul Revere-like sprint set the camp ablaze with nervous talking.

Mayor Antonio Villaraigosa said he decided that it was time to evict Occupy L.A. protesters from the City Hall lawn after learning that there were children staying there.

Given the smattering of assaults and other incidents reported at the camp, “the chaos out there could produce something awful,” he said in an interview with the Los Angeles Times.

The mayor, a former union organizer and former president of the Los Angeles chapter of the American Civil Liberties Union, said he and LAPD Chief Charlie Beck jointly made the decision to allow overnight camping on the lawn in the hope of charting a “different path” with protesters. That was, he said, in part because he respects many of their views.

Many at the tent city -- which grew to include its own library, a multitude of committees and even a schedule of yoga classes -- were drawn by outrage at economic policies that they say favor the rich. But many also pledge allegiance to a variety of other causes, including legalizing marijuana and ending the Federal Reserve.